Apparatus for and methods of processing food, such as by cooking, heating, cooling and freezing, are well known.
An example of a typical blast freezer is the "Linetray Freezer" sold by Litton Industries which has a housing, a first conveyor that carries food product horizontally into the housing, a second conveyor that carries the food product vertically upward withing the housing past a series of fans which circulates the air in the housing, and a third conveyor horizontally carries the food product across the top of the housing to a storage bin wherein the food product is stored within the housing in the frozen condition. One disadvantage of this type freezer is that the motors used are disposed in the housing which adds heat to the housing and thereby lowers the efficiency of the blast freezer. Another disadvantage is that the fans do not circulate the fluid within the housing in a fashion promoting the most useful amount of heat transfer to these remote portions of the housing which thereby lengthens the time the food product must be disposed within the housing. A further disadvantage of this type freezer is that the control of the fluid circulating within the housing is not as accurate as one would desire thereby causes certain areas of the vertically disposed food product to receive larger quantities of air than other portions of the food product which causes variations in freezing between top, bottom and middle section of the vertically disposed rack.
Another example of apparatus used to process food is the oven disclosed in U.S. Pat. No. 3,261,343 by Tibell which includes a housing adapted to receive a moveable rack which supports vertically disposed layers of food product. Side walls are provided within the housing with slots extending therethrough to direct fluid flow from one wall to the other wall between the layers of food product to thereby induce circulation of the air in the housing around each layer of food product. This apparatus also fails to properly control the flow of the fluid between each layer of food product to balance the top, middle and bottom heat transfer to the food product. Further, this apparatus does not control the flow of the fluid for redirection between alternate layers of food product to thereby induce circulation of the fluid around each layer of the food product.
Accordingly, it is an object of the present invention to provide a food processing unit and a method of processing a food product which directs the flow of fluid in a substantially horizontal direction through spaces between layers of food product and distributes the flow of the directed fluid within the housing to induce circulation of fluid throughout the housing such as to provide a balanced heat transfer from the fluid throughout the vertically disposed layers of food product.
Further, it is an object of the present invention to provide a food processing unit and a method of processing a food product which controls the circulation of the fluid throughout the housing so as to enable accurately controlled heat transfer at remote portions.
Further, it is an object of the present invention to provide a food processing unit and a method of processing a food product which controls the circulation of the fluid within a housing so as to direct a flow of fluid from a first side through those spaces located prior to every other layer of food product and then redirect the flow of fluid toward the first side in those spaces adjacent the spaces through which the fluid is initially directed to induce circulation of the fluid within the housing around each layer of food product.
Further, it is an object of the present invention to provide a processing unit which circulates the fluid within the housing so as to prevent heat from motors used with such unit to affect the efficiency of such unit.
In accordance with the present invention, a food processing unit uses a housing adapted to receive vertically disposed layers of food product. Heat transfer apparatus is provided to control the temperature of the fluid within the housing when processing the food product. Apparatus is further provided to supply the pressurized fluid within the housing and apparatus is used to direct the flow of fluid from the pressurized fluid supplying apparatus to a substantially horizontal direction through spaces between layers of food product. Apparatus is further provided which distributes the flow of directed fluid within the housing to induce circulation of the fluid within the housing such as to provide zones of controlled heat transfer from the fluid to the food product vertically throughout the housing.
Further, in accordance with the invention, a food product processing unit includes a housing used in processing vertically disposed layers of food product. Heat transfer apparatus is provided for controlling the temperature of the fluid environment within the housing when processing the food product. Apparatus is further provided for supplying a pressurized fluid in the cabinet. Apparatus is disposed on a first side of the layers of food product for directing a flow of fluid from the pressurized fluid supplying means in a substantially horizontal direction through those spaces located prior to every other layer of food product and apparatus is disposed on the side of the layers of food product opposite the first side for redirecting the directed flow of fluid toward the first side in those spaces adjacent the spaces through which the fluid is initially directed by the directing means to induce circulation of the ambient fluid within the housing around each layer of food product.
Further, in accordance with the invention, a method of processing a food product comprises the steps of positioning layers of vertically disposed food product within the housing. The temperature of the environment within the housing is controlled to process the food product. A pressurized fluid is supplied in the housing and a flow from the pressurized fluid is directed horizontally between alternate layers of the food product with the directed fluid being distributed vertically within the housing such that the heat transfer is provided in zones of controlled heat transfer from the ambient fluid within the housing to the layers of food product.
Further, in accordance with the invention, a method of processing a food product comprises the steps of positioning layers of vertically disposed food product within a housing. A pressurized fluid is supplied in the housing and a flow of fluid from the pressurized fluid supply is directed in a substantially horizontal direction through spaces just prior to every other layer of food product in the housing. The directed fluid is then redirected to flow toward the first side in those spaces adjacent the spaces through which the fluid is directed to induce the ambient fluid in the housing to circulate around each layer of food product. The temperature of the fluid within the housing is controlled to process the food product within the housing.